Valve mechanism and valve tappet therefor



July 26, 1927.

. s. I; FEKETE ET AL,

VALVE MECHANISM AND VALVE TAPPET THEREFOR Filed June 192.1

a m M Q a TL yM/M.

. Tu I 1. I f fi Patented July26, 1927.

UNITED STATES 1,637,020 PATENT oFFica.

summer: I. runners, on nn'rnorr, 'Ann RALPH n. WHISLER, on HALFWAY,MICHIGAN,

AssIGnoBs '10 Essnx morons, or DETROIT, MICHIGAN, A conronarron or MICHIGAN.

VALVE MECHANISM AND VA LVE TAPPET THEREFOR.

Application filed June 21, 1921.' Serial No. 479,368.

Our invention relates to valve mechanisms for poppet valve-operatedinternal combustion engines, and the object of the invention is toprovide a valve mechanism which shall eliminate most of the noise causedby the valve mechanism. While the invention relates broadly to the valvemechanism, it may be embodied in a more specificform in a valve tappet.7 As is Well known to those skilled in the art, it is necessary toprovide a clearance between the lower end of the valve stem and the topof the valve tappet or adjusting screw to allow for the expansion andcontraction of the parts, since otherwise the valve would not seat whenthe engine is hot. We have ascertained that the noise produced by valvemechanisms of this character is due to the blow struck on the lower endof the valve stem by the tappet adjusting screw. Ourinvention does awaywith the noise by reducing the clearance between the parts while at thesame time making adequate provision for expansion.

Broadly considered, our invention consists in incorporating in a movingpart of the valve mechanism a system of difl'erent metals producingdifferential expansion so that the total length of the parts, consideredas a single system, will remain substantially the same throughout therange of working temperatures of the engine. In the preferred embodimentof our invention, the differential system forms a part of the valvetappet, as this has certain practical advantages in manufacture andoperation, but we do notlimit ourselves to this form.

It will also be understood that under ordinary circumstances it is notnecessary to invention in its preferred form.

Referring now to the drawing, at 11 is shown the cam, at 12 a portion ofthe engine block, at 13 a valve guide, at 14 a valve spring and at 15 avalve stem, the head heproportion the length of parts with absolute Iview of the valve mechanism embodying ouring designated 16. The-tappetguide is shown at 17. lVithin-this guide is located a tubular steeltappet 18 of ordinary cononly for a short distance at the outer or topend of the tappet member. Thearea. of contact is designated at 0. Belowthis area of contact, there is aclearance (Z between the outside of thealuminum sleeve 19 and the inner wall of the exterior tappet member 18.-Mounted in the bore of the aluminum sleeve 19 is a steel sleeve 20 whichcarries the adjusting screw 21 and an adjusting nut 22, these being ofthe ordinary construction. There is a slight clearance between the innerdiameter of the aluminum sleeve and the steel sleeve 20. This clearanceis indicated at e in the. drawin s and 30 is greatly exaggerated for thesake 0 clear ness.

From the foregoing it will be seen that r the direction of elongation ofthe aluminum sleeve due to expansion is opposite to the direction ofelongation of the steel parts of the valve mechanism, and since theco-eflicient of expansion of the aluminum sleeve is much greater thanthat ofsteehthe expansion of one compensates to that extent for theexpansion of the other.

In practice, the adjusting screw 21 is set when the motoris cold so thatits head makes contact with the lower end of the valve stem but will notlift the valve off its 5 seat. When the engine is hot, it will be foundthat the valve seats perfectly but that the noise produced by the blowof the tappet adjusting screw on the lower end of the valve ispractically eliminated.

What we claim is 1. A poppet valve mechanism havin two separate movableelements arrange fordriving connection, one ofvsaid elements beingcomposed of a plurality of parts con- 105 nected to expand insubstantially parallel directions and tend to compensate for changes intemperature and thereb substantially maintain a predetermine relationwith the other element.

2. A poppet valve mechanism having one of its driven elements composedof a lurality of parts some of which are of meta hav ing differentcoefficients of expansion, said parts being arranged so that theexpansion of one of them tends to compensate that of another.

3. A poppet valve mechanism having one of its moving elements composedof a plurality of parts, said parts being constructed and arranged insubstantially parallel relation to cause said element to remain asubstantially constant lentgth under the expansion and contraction o theseveral parts.

4. A poppet valve mechanism havin one of its moving elements composed ofa p urality of parts some of which are of metals having differentcoeflicients of expansion, said parts being constructed and arranged tocause'said element to remain a substantially constant length under-theexpansion and contraction of the several parts.

5. A poppet valve mechanism having a movable element some of the partsof which are made of steel, and another part of which is made of metalhavin a higher co-eliicient of expansion than stee the total length ofthe steel parts being reater than that of the other part, said mechanismbeing arranged so that the direction ofelon ation of the steel parts dueto expansion wi 1 be opposite to that of the part having the higherco-eln? cient of expansion,

6. A valve tappetcom rising three parts two of which are composed of ametal havin a relatively low coeflicient of expansion and the third ofwhich is of a metal havin a relatively higher coefiicient of expansion,said parts being arran ed with relation to each other so that the eongation of said last named part tends to compensate the elongation ofsaid first named parts.

7. A valve tappet com risin three .parts, two of which are steel an thet ird of which is aluminum, said parts being arranged with with the camand an interior steel member for contact with the end. of the valve stemand a third member interposed between the said two first-mentionedmembers and composedof a metal having a greater coefficient of expansionthan steel, the whole being arranged so that the' elongation of theintermediate member due to expansion will he in a direction opposite tothe elongation of the steel members.

9. A valve tappet comprising a tubular exterior tappet member, analuminum sleeve located within the bore of said tappet member andsecured thereto at the outer end only, and an interior steel member forengagement with the stem of "the valve, said interior member bein incontact with the aluminum sleeve at the inner endso that the elongationof the aluminum member due to expansion will compensate for theelongation of the steel member.

10. A poppet valve mechanism some of the parts of which are made ofsteel and another part oi which is made of a metal having a higherco-eflicient of expansion than steel; said mechanism being arranged sothat the direction of elongation of the steel parts will be 0 posite tothat of the part having highertures.

S'IZEPHEN I. FEKETE. RALPH H. WHISLER.

co-e cient of expansion, and the length of

